During Phase I, a breadboard Micropolarimeter was developed and demonstrated. This instrument is comprised of a stabilized 2-frequency laser, a modified microscope, and a detector/phasemeter module: it is capable of quantitatively measuring the birefringence of microscopic samples with a sensitivity of better than 1/10,000-wavelength, and with a 10 KHz bandwidth. The proposed Phase II has as its objectives: (1) build a prototype Micropolarimeter with built-in provision for scanning; (2) modify the design to include the capability for quantitatively measuring the optical thickness of microscopic phase objects (Microphasemeter); (3)\further modify the design to allow its use with reflective specimens (to accomodate industrial applications); and (4) carry out and publish three research projects based on measurements made with the improved Micropolarimeter (1. Birefringence changes induced by axon membrane action potentials; 2. Birefringence and phase imagery of mitotic spindle fibers; and 3. Measurement capabilities of a Micropolarimeter/Microphasemeter). These publications will inform the scientific community of the availability and capabilities of the Micropolarimeter.